Inputs and Outputs Notes
Six-Channel System Amplifier: The JL Audio A6450 is a class AB system
amplifier that is rated at 70 Watts RMS x 6-channel in
4 ohm at 20 to 20,000Hz with a signal-to-noise-ratio of 104 dB and a total
harmonic distortion of 1% while receiving 14.4 Volts or 45 Watts RMS x 2-channel
in 4 ohm with a total harmonic distortion of 0.08% while receiving 12.5 Volts.
The amplifier can be bridged to output 220 Watts RMS x 3-channel in 4-ohm at
14.4 Volts or 150 Watts RMS x 3-channel in 4-ohm at 12.5 Volts. The main purpose
of a 6-channel system amplifier is to give you the ability and convenience to
power two pair of full-range speakers and a pair of subwoofers simultaneously
with one amplifier.
Absolute Symmetry A/B Circuitry: The JL Audio full-range amplifier
benefits from a patented technology called Absolute Symmetry to deliver amazing
fidelity with extremely low distortion over a wide range of load impedances. The
JL Audio amplifier features a revolutionary Class A/B circuit that employs
identical N-Channel MOSFET transistors for push and pull with true buffering
from the load impedance. This is accomplished via a patented circuit that
reverses the operation of one of the transistors in each pair to achieve
absolute power symmetry and extremely low distortion over a wide range of load
Simplified Gain Setting: The A-Series amplifier makes setting the
gain level of the amp via the input sensitivity control very simple. All you
need is Digital AC Voltmeter (142TK12V, sold separately) and a Test CD Disc
(503CD104, sold separately) with a sine-wave test-tone recorded at 0 dB
reference level in the frequency range to be amplified for that set of channels
(50 Hz for subwoofer channels, 1 kHz for a midrange application).
Differential-Balance Inputs: The JL Audio amplifier features
differential-balanced input architecture to effectively control noise and ensure
compatibility with a wide variety of source units, including many OEM
systems. Without resorting to line output converters, you can directly connect
most OEM source units to the JL Audio amplifier without creating any noise or
compatibility issues. Unlike conventional single-ended inputs, the
differential-balanced design does not connect one side of the audio signal to
chassis ground. This eliminates any voltage sensitivity between one input
terminal and ground and greatly reduces the incidence of alternator whine in a
typical car audio installation. The A6450 amplifier provides range switching
on each of its inputs via the "Input Voltage" switch. This permits connection to
a wide range of source voltages while retaining excellent sensitivity setting
Note: The Channel 5 & 6 input section is designed to accept only
line-level signals. You will need two speaker wire to RCA adaptors (136CLR2SW, sold
separately) to connect this amplifier to your headunit via speaker-level.
Input Mode: The A6540's input section allows you to send signal to the
amplifier section through the use of two, four or six differential-balanced
inputs. Input connections on the amplifier are via three pairs of traditional
RCA-type jacks. You can send six discrete channels of audio signal into the
amplifier by connecting all six inputs to the six preamp outputs on back of your
headunit via three sets of stereo RCA cables. You can also connect the amplifier
using only channels 1, 2, 3 & 4 and the amplifier will sum those channels to
create an audio signal for channels 5 & 6. If you use only two channels of input
to deliver signal to all six amplifier channels, it will be necessary to split
the two signals with an RCA Y-adapter to connect to channels 1, 2, 3 & 4 so
those inputs can sum the input of channels 5 & 6.
Active Crossover: The A-series amplifier provides a crossover network to fine
tune your system effectively and accurately. The A6450 offers the following
independent crossover adjustments for the 1 & 2, 3 & 4, and 5 & 6 channels.
Filter Mode: The amplifier allows you to select either a Low Pass, High
Pass or Full-Range operation of the amplifier's 1 & 2 channels, 3 & 4
channels, and 5 & 6 channels.
Variable Frequency: You can set the amplifier's Low Pass or High Pass
crossover from 50 to 200 Hz for channels 1 & 2 and channels 3 & 4.
Bass Controls: The bass boost circuit of the A-Series amplifier offers
the following controls that only effect channels 5 & 6 of the amplifier.
Bass Boost: The amplifier is equipped with a fixed +6dB, 48 Hz
Remote Bass Port: The amplifier is equipped with a connection for
a wired Remote Bass Control (136RBC1, sold separately) that allows fully
variable boost control (0-12dB) from the front of your vehicle.
Advanced Rollback Protection: Should an A-series amplifier ever
intelligent, unregulated power supply reacts by limiting available peak voltage
until the amplifier returns to a safe temperature range. Likewise, if an
impedance lower than optimal for the amplifier is present at the outputs, the
A-series amplifier will roll back peak voltage to protect itself without
Note: There is only one condition that will shut down the
A-Series amplifier completely and that is if the battery voltage of your
vehicle drops below 10 volts.
Protection Circuitry With Status Indicator Lights: There are
two status indicator lights on the right side of the amplifier.
Power (Green): This LED lights green to indicate that the
amplifier is turned on and operating normally.
Protect (Red): The Protection LED lights Red to indicate the
amplifier's protection circuitry has been activated to prevent product
failure due to a short-circuit or a dangerously low impedance connected to
the amplifier's outputs.
Inputs and Outputs Notes
Left Side Of Amplifier:
Power and Ground: The JL Audio amplifier's set-screw Power and Ground
connections are designed to accept 8 to 4 AWG power wire.
Remote Turn-On: The A-series amplifier's set-screw turn-on lead will
accept 18 to 12 AWG wire.
Speaker Outputs: The A6450 amplifier's twelve set-screw speaker terminals
will accept 16 to 8 AWG speaker wire.
Right Side Of Amplifier:
Preamp Inputs: The amplifier features three sets of differential-balanced
RCA jack inputs. The amplifier's input level can be set to Low (200mV-2V RMS)
when connecting the amplifier to a low-level preamp signal or set to High
(800mV-8V RMS) when connecting the amplifier to a high-level speaker signal.
Remote Bass Port: The amplifier is equipped with a connection for a
wired Remote Bass Control (136RBC1, sold separately).